GB/T 5121.14-1996 Chemical analysis methods for copper and copper alloys - Determination of manganese content
Some standard content:
National Standard of the People's Republic of China
Chemical analysis methods for copper and copper alloys
Determination of manganese content
Copper and copper alloys--Determination of manganese content Part I Method 1 Determination of manganese content by potassium periodate spectrophotometry 1 Scope
This standard specifies the method for determining the manganese content in copper and steel alloys. This standard is applicable to the determination of manganese content in copper and copper alloys. Determination range: 0.030%~~2.50%. 2 Reference standards
GB/T5121.141996
Replacement (5122.4
(H3 5122. 10)8:
GH 6520.6
GB 8550. 17
The following standards contain provisions that constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4--88 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB146778 General principles and general provisions for chemical analysis method standards for metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB6379-86 The precision of the test method is determined by inter-laboratory testing Standard test Repeatability and reproducibility of the method 3 Method summary
The sample is dissolved in a mixed acid of hydrofluoric acid, boric acid and nitric acid. Potassium periodate is added to oxidize manganese to permanganic acid, and the base color solution obtained by selectively reducing permanganic acid with sodium nitrite is used as a reference. The absorbance is measured at a wavelength of 530nm on a spectrophotometer. 4 Reagents
4.1 Dissolving agent: Mix 300ml of boric acid solution (40g/l.), 30ml of hydrofluoric acid (pl.13g/ml.), 500ml of nitric acid (pl.42g/ml.) and 150mL of water. Store in a plastic bottle. 4.2 Dilution: Add to Add 1 mL of sulfuric acid (ol.84 g/mL) to 100 mL of boric acid solution (40 g/L). When boiling, add a few grains of potassium periodate to oxidize organic matter that may reduce permanganate. 4.3 Potassium periodate solution (50 g/L): Prepare with nitric acid (1+3). 4.4 Sodium nitrite solution (20 g/L): Prepare when needed. 4.5 Manganese standard storage solution.
4.5.1 Take a few grams of pure manganese and place it in a 250 mL beaker containing about 100 mL of water and 60-80 mL of sulfuric acid (1+3). After stirring for a few minutes, pour out the acid solution, wash with water for a few times, and then place it in ketone. , stir, pour out the acetone. Dry in a 100℃ constant temperature oven for about 2 minutes. Take it out, put it in a desiccator, and cool it.
4.5.2 Weigh 1.000g of pure manganese (4.5.1) and place it in a 300ml beaker, add 80mL of water, slowly add 40ml of sulfuric acid (o1.84g/ml) to dissolve, boil for several minutes, and cool it. Transfer it to a 1000ml container, dilute it to the scale with water, and mix it with a spoon. This solution 1ml. 1mg manganese.
Approved by the State Administration of Technical Supervision on November 4, 1996, implemented on 199704-01
GB/T 5121.14-1996
4.6 Manganese standard solution: Pipette 10.00 mL of manganese standard stock solution into a 100 mL volumetric flask, dilute to scale with water and mix well. This solution contains 0.1 mg manganese per mL.
5 Instruments
Spectrophotometer.
6 Analysis steps
6.1 Test materials
Weigh the sample according to Table 1. Accurate to 0.0001 g. Table 1
Manganese content
0.030~0.15
>0. 15~0. 50
>0. 50~1.00
>1. 00~2. 50
Sample volume
Total volume of test solution
Carry out two independent determinations and take the average value. 6.2 Blank test
Carry out a blank test with the sample.
6.3 Determination
Volume of test solution
Addition of solvent
Amount of water added
6.3.1 Place the sample (6.1) in a 300mL conical flask, add 50mL of solvent, heat to dissolve. Add 20mL of water. Boil for 5min to remove nitrogen oxides.
6.3.1.1 When the manganese content is 0.030%~~0.50%, proceed as per 6.3.2. 6.3.1.2 When the manganese content is greater than 0.50%~2.50%, transfer the solution according to Table 1 into a 300mL conical flask, add solvent and water, and boil for 5 minutes.
6.3.2 Add 5mL potassium periodate solution to the boiling solution and continue boiling for 5 minutes, then immerse the conical flask in a boiling water bath for 20 minutes and cool. Transfer to a 100mL volumetric flask, wash with diluent and dilute to the mark, and mix well. 6.3.3 Transfer part of the solution into a 1cm absorption tube, and use the background solution obtained by adding 1 drop of sodium nitrite solution to the absorption tube in advance and then pouring the color developing solution as the reference, and measure its absorbance at a wavelength of 530nm on a spectrophotometer. 6.3.4 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding manganese content from the working curve. 6.4 Drawing of the working curve
6.4.1 Transfer 0, 3.00, 6.00, 9.00, 12.00, and 15.00 ml of the manganese standard solution to a 300 ml conical flask, add water to 20 ml, add 50 ml of the solvent, and boil for 5 min. The following is carried out according to 6.3.2 to 6.3.3. 6.4.2 Subtract the absorbance of the reagent blank and draw the working curve with the manganese content as the horizontal axis and the absorbance as the vertical axis. 7 Expression of analytical results
Calculate the percentage of manganese according to formula (1):
m, ·V. × 10-3
Mn(%)=
In the above formula: m is the amount of manganese found from the working curve, mg; 266bZxz.net
is the total volume of the test solution, mL;
V… is the volume of the test solution taken, nL;
m, is the mass of the test material, g.
GB/T 5121. 14
The result is expressed to two decimal places; if the manganese content is less than (.10%, it is expressed to three decimal places. 8 Precision
The precision of this standard was determined by the test results of 8 laboratories in 1993 (see Appendix A·Table A1) at 8 levels. See Table 2 for precision.
Level range㎡
0.030～2.50
Igr aa
Repeatability?
-1. 759 2+0. 91 Igm
ReproducibilityR
1. 487 6 p0. 75 lgm
If the difference between two independent test results exceeds the repeatability and reproducibility values calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Part 2 Method 2
9 Scope
Determination of manganese content by ammonium ferrous sulfate titration
This standard specifies the method for the determination of manganese content in copper and copper alloys. This standard is applicable to the determination of manganese content in copper and copper alloys. Determination range: >2.50%~15.00%. 10 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards All of them will be revised. Parties using this standard should explore the possibility of using the latest version of the following subtitles GB1.4-88 Standardization work guidelines for chemical analysis method standards GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB6379-86 Precision of test methods The repeatability and reproducibility of standard test methods are determined through inter-laboratory tests 11 Method summary
The sample is dissolved in nitric acid, and manganese is oxidized to trivalent manganese with ammonium nitrate in a phosphoric acid medium. It is titrated with ammonium ferrous sulfate standard titration solution using phenyl anthranilic acid as an indicator.
12 Reagents
12.1 Ammonium nitrate.
12.2 Phosphoric acid (pl.69g/mL).
12.3 Nitric acid (1+1).
12.4 Sulfuric acid (1+9).
12.5 Phenyl-o-aminobenzoic acid solution (2g/1): weigh 0.2g of phenyl-o-aminobenzoic acid and place it in a 150ml beaker. Add 100ml of sodium carbonate solution (2g/1.) and heat to dissolve completely. 12.6 Potassium dichromate standard solution [c(1/6KzCrz0,)=0.01500mol/l.1: weigh 0.7355g of standard potassium dichromate that has been pre-dried at 140-150℃ (dried to constant weight and placed in a desiccator to cool to room temperature) is placed in a 300ml beaker, dissolved in water, transferred to a 1000ml volumetric flask, diluted to scale with water, and mixed. 12.7 Standard titration solution of ammonium ferrous sulfate ic[(NH),Fe(SO)2·6H2O7=0.015mol/L) 267
12.7.1 Preparation
GB/T5121.14.1996
Weigh 5.88g of ammonium ferrous sulfate and place it in a 400mL beaker. Add 250mL of sulfuric acid (1+4) to dissolve it. Transfer it to a 1000ml volumetric flask, dilute to scale with water, and mix. 12.7.2 Calibration
Pipette 25.00mL potassium dichromate standard solution (12.6), add 20ml water, 10mL sulfuric acid and phosphoric acid mixture (1+1-t1). 2-4 drops of phenyl anthranilic acid solution (12.5), and titrate the solution with ammonium ferrous sulfate standard titration solution (12.7.1) until bright yellow is the end point.
Calculate the actual concentration of ammonium ferrous sulfate standard titration solution according to formula (2): 0. 015 00V
Where: c-
actual concentration of ammonium ferrous sulfate standard titration solution, mol/L; -volume of potassium dichromate standard solution pipetted, ml; V. -—volume of ammonium ferrous sulfate standard titration solution consumed during calibration, mL29
Take three portions for calibration, and the range of the volume of ammonium ferrous sulfate standard titration solution consumed during calibration shall not exceed 0.10mL, and take the average value of H. Otherwise, recalibrate.
13 Analysis steps
13.1 Test material
Weigh the sample according to Table 3, accurate to 0.0001g. Table 3
Amount, %
≥2.50~8.00
8. 00~15.00
Carry out two independent determinations and take the average value. 13.2 Determination
13.2.1 Place the test material (13.1) in a 300ml conical flask, add 5mL nitric acid (12.3), and heat until it is completely dissolved. 13.2.2 Add 15mL phosphoric acid (12.2) and mix. Place on a high-temperature electric furnace and heat until phosphoric acid fumes just come out, then remove. Place for 20~30s, add 1~2g ammonium nitrate (12.1), and immediately shake and blow to remove nitrogen oxides. Let stand for 1-2 minutes, add 30 ml of sulfuric acid (12.4), and cool to room temperature with running water.
13.2.3 Titrate the solution with standard ammonium ferrous sulfate solution (12.7) until it turns slightly red, add 2-4 drops of phenylanthranilic acid solution (12.5), and continue titrating until it turns bright yellow. 14 Expression of analysis results
Calculate the percentage of manganese according to formula (3):
Mn(%) = V, × 0. 054 94
Wherein: c—--actual concentration of standard ammonium ferrous sulfate titration solution, mol/L; V——volume of standard ammonium ferrous sulfate titration solution consumed during calibration, mL; mo
0. 054 94
mass of sample·g:
mass of manganese equivalent to 1.00mL standard ammonium ferrous sulfate titration solution ic［(NH,),Fe（S,）·6H0)=1.(000mol/L), g/mol.
The obtained result is expressed to two decimal places.
15 Precision
GB/T5121.141996
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A, Table A2) at 5 levels selected in 1993. See Table 4 for precision.
Level range m
>2.50%～15.00%
Repeatability
r=0. 014±0. 002 1 m
Reproducibility R
R --- 0. 054 ↓ 0. 002 9 m
If the difference between two independent test results exceeds the repeatability and reproducibility values calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
GB/T 5121.14
Appendix A
(Standard Appendix)
Raw data of precision test
Ping, %
Laboratory
GB/T 5121, 14-- 1996
Ping, %14
Appendix A
(Standard Appendix)
Raw data of precision test
Ping, %
Laboratory
GB/T 5121, 14-- 1996
Ping, %14
Appendix A
(Standard Appendix)
Raw data of precision test
Ping, %
Laboratory
GB/T 5121, 14-- 1996
Ping, %
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